The present invention is directed to a prophylactic apparatus for cleaning teeth with both a flow of air containing powder particles and a flow of water. The apparatus includes a hand piece having a nozzle opening for both the air that contains the abrasive particles and also an opening for a fluid such as water and these nozzle openings are connected to the respective feed lines for the air laden with abrasive particles and for the water.
Several devices are known in which a cleaning of the teeth is obtained by utilizing a hand piece which has a nozzle through which a jet of gaseous medium such as air containing abrasive particles is directed onto the surface of the teeth. The hand piece will also have a nozzle for directing a liquid jet such as a water jet which can be applied in the immediate vicinity of the surface of the tooth or immediately at the point on the surface of the tooth in which the jet of abrasive powder is directed.
However, the employment of these known apparatuses have several difficulties and disadvantages which require high maintenance costs. In particular, the known devices utilize a structure for obtaining a mixture of the air and powder which does not always permit the obtaining of a uniform distribution of the powder in the gaseous jet. Moreover, the known devices tend to become clogged and require daily cleaning after each stoppage of the apparatus. Finally, the known apparatuses on the whole are very heavy and cumbersome to use.